# encoding: utf-8
class Car():
    """一次模拟汽车的简单尝试"""
    def __init__(self, make, model, year):
        """初始化描述汽车的属性"""
        self.make = make
        self.model = model
        self.year = year
        self.odometer_reading = 50

    def get_descriptive_name(self):
        """返回整洁的描述性信息"""
        long_name = str(self.year) + ' ' + self.make + ' ' + self.model
        return long_name.title()

    def read_odometer(self):
        """打印一条指出汽车里程的消息"""
        print("This car has " + str(self.odometer_reading) + " miles on it.")

    #def update_odometer(self, mileage):
    #    """将里程表读数设置为指定的值"""
    #    self.odometer_reading = mileage

    def update_odometer(self, mileage):
        """
        将里程表读数设置为指定的值
        禁止将里程表读数往回调
        """
        if mileage >= self.odometer_reading:
            self.odometer_reading = mileage
        else:
            print("You can't roll back an odometer!")

    def increment_odometer(self, miles):
        """将里程表读数增加指定的量"""
        self.odometer_reading += miles

class Battery():
    """一次模拟电动汽车电瓶的简单尝试"""
    def __init__(self, battery_size=85):
        """初始化电瓶的属性"""
        self.battery_size = battery_size

    def describe_battery(self):
        """打印一条描述电瓶容量的消息"""
        print("This car has a " + str(self.battery_size) + "-kWh battery.")

    def get_range(self):
        """打印一条消息， 指出电瓶的续航里程"""
        if self.battery_size == 70:
            range = 240
        elif self.battery_size == 85:
            range = 270
        message = "This car can go approximately " + str(range)
        message += " miles on a full charge."
        print(message)

class ElectricCar(Car):
    """电动汽车的独特之处"""
    def __init__(self, make, model, year):
        """
        初始化父类的属性， 再初始化电动汽车特有的属性
        """
        super().__init__(make, model, year)
        self.battery = Battery()

#my_new_car = Car('audi', 'a4', 2016)
#print(my_new_car.get_descriptive_name())
#my_new_car.read_odometer()
#
#my_new_car.odometer_reading = 23
#my_new_car.read_odometer()
#my_new_car.update_odometer(22)
#print(my_new_car.odometer_reading)
#
#my_new_car.update_odometer(10000)
#print(my_new_car.odometer_reading)
#
#my_new_car.increment_odometer(5000)
#print(my_new_car.odometer_reading)